National Insurance for Employees: Rates, Thresholds and How It Differs from Income Tax

How employee NI is calculated

Employee National Insurance contributions are calculated on earnings between the primary threshold (£12,570 per year in 2026/27) and the upper earnings limit (£50,270 per year). The rate in this band is 8%. Above the upper earnings limit, the rate drops to 2% with no upper cap.

Unlike income tax, NI has no personal allowance, no progressive bands beyond the two rates, and no annual reconciliation. It is calculated on monthly earnings using monthly thresholds (approximately £1,047 lower and £4,189 upper per month). If you earn £6,000 in one month and £2,000 in the next, NI is calculated independently each time, there is no smoothing across the year.

This monthly-only calculation can produce an apparent overpayment in months with high earnings compared to a simple annual calculation. There is no refund mechanism for NI, what is deducted stays deducted, which is why a calculator should always show both income tax and NI separately.

• 8% rate: earnings between £12,570 and £50,270 per year (2026/27).
• 2% rate: earnings above £50,270, no upper cap.
• Calculated monthly; no annual reconciliation or refund.
• No personal allowance equivalent below the primary threshold.

Key differences from income tax

Income tax is cumulative across the year and self-corrects across months. NI does not. A large bonus in one month pushes that month's NI calculation into a different position, with no correction in later months. This is why the two deductions should be modelled separately for accurate payslip estimates.

Income tax has the personal allowance taper at £100k and the additional rate band above £125,140. NI has none of this, the 2% rate simply continues above the upper earnings limit regardless of how high the salary goes. At very high salaries, NI becomes a much smaller proportion of deductions than income tax.

Both are paid alongside each other as separate deductions on the same payslip, which is why many people quote them together as a combined rate. But for planning purposes, especially around salary sacrifice, pension, and threshold effects, treating them separately gives more accurate results.

• Income tax: cumulative, corrects itself across the year.
• NI: monthly only, no year-end correction.
• Income tax: tapers allowance at £100k; NI has no similar structure.
• Both are visible separately on your payslip as distinct deductions.

When NI contributions stop or change

Employees over State Pension age do not pay employee National Insurance even while remaining in work. Employer contributions continue regardless of employee age.

If you are self-employed, NI works differently, Class 2 and Class 4 contributions apply instead of Class 1 employee NI. The rates and thresholds differ substantially, which is one reason why employed-to-self-employed transitions change net income noticeably even on the same gross.

Director loans and dividend income do not attract employee NI in the same way as salary. This is central to the tax efficiency argument for operating as a limited company, though other factors including Corporation Tax and dividend tax need to be modelled for a complete comparison.

• State Pension age: employee NI stops, employer NI continues.
• Self-employed: Class 2 and Class 4 NI apply instead.
• Dividends: no employee NI (subject to dividend tax instead).
• Directors: NI treatment varies depending on salary/dividend split.